Control system for periodically feeding nutrient solutions to hydroponic plant beds

ABSTRACT

A control system and circuit for periodically pumping nutrient solutions to hydroponic plant beds. Two twenty-four hour electric clock switches are so interconnected that the first one is adapted to periodically make contact at preselected intervals and for preselected time periods, while the second one is adapted to disable the first one during a preselected (relatively dark) part of each day. The second (or day-night) switch also controls a solenoid valve so that replenishing water can be fed to a storage vat for nutrient solution only at night to avoid the danger of vat overflow. Another feature is the provision of an outlet connected across the pump circuit to permit a common electric clock to be used to time a pumping cycle or a series (day, week, etc.) of cycles.

United States Patent Holmes 1 June 17, 1975 HYDROPONIC PLANT BEDS [76] Inventor: Floyd W. Holmes, 7302 Rolliston St., Jacksonville, Fla. 32208 [22] Filed: Jan. 29, 1974 [21] Appl. No.: 437,661

[52] US. Cl 47/1.2; 137/624.l1

[51] Int. Cl A0lg 31/00 [58] Field of Search 47/1.2, 14, 16, 38; 137/62411-62415, 624.21

[56] References Cited UNITED STATES PATENTS 2,814,912 12/1957 Chew 47/1.2 X

2,928,211 3/1960 Martin 47/l.2

3,131,064 4/1964 Malchair 47/1.2

3,168,797 2/1965 Patassy 47/38 3,233,366 2/1966 Nutile et a1. 47/16 3,323,253 6/1967 Robins 47/1.2

3,451,162 6/1969 Rasmussen 47/1.2

3,458,951 8/1969 Martin 47/1.2

Primary Examiner-Robert E. Bagwell Attorney, Agent, or FirmEdwin E. Greigg ABSTRACT A control system and circuit for periodically pumping nutrient solutions to hydroponic plant beds. Two twenty-four hour electric clock switches are so interconnected that the first one is adapted to periodically make contact at preselected intervals and for preselected time periods, while the second one is adapted to disable the first one during a preselected (relatively dark) part of each day. The second (or day-night) switch also controls a solenoid valve so that replenishing water can be fed to a storage vat for nutrient solution only at night to avoid the danger of vat overflow. Another feature is the provision of an outlet connected across the pump circuit to permit a common electric clock to be used to time a pumping cycle or a series (day, week, etc.) of cycles.

T0 l UMPS T0 WATER INPUT SOLENOID CONTROL SYSTEM FOR PERIODICALLY FEEDING NUTRIENT SOLUTIONS TO HYDROPONIC PLANT BEDS BACKGROUND OF THE INVENTION It is known to program the periodic pumping of nutrient solutions to hydroponic plant beds and to employ float-operated valves to maintain storage vats at desired fullness. But it is not known to employ two clock switches, the first of which is adjustable as to both frequency and duration of pump operation, and the second of which is adjustable on a day-night basis to disable the first clock switch during dark hours and also to disable a conventional vat-filling solenoid valve during possible pumping time, to avoid vat overflow from drain-back solution following a pumping cycle. It is further not known to provide for plugging-in common electric clocks to indicate the time of operation of one or a series of pump operation(s).

OBJECTS OF THE INVENTION It is accordingly an object of the present invention to provide a hydroponic feeding system having two clock switches, one to provide both frequency and duration variable pumping cycles, and the other to provide for disabling the first one during night hours and to enable opening of a vat-filling valve only during night hours.

It is a further object to provide a pump-circuitconnected outlet by which a common electric clock can be employed to indicate the duration of one or a series of pump operations.

It is still a further object to mount most of the small and/or occasionally replaced elements on the hinged cover panel of the metal cabinet.

These and other objects and advantages will become apparent as the following detailed description proceeds.

THE DRAWING The single FIGURE of the drawing is primarily a schematic wiring diagram of the circuitry of the invention.

With reference now to the drawing, the parts of the control apparatus are all mounted within or on a vertically oriented panel-type metal cabinet with a hinged front-pull cover panel, shown in phantom and designated as part C. The cover panel C is hinged at the vertical hinge line H for swinging, from its open position shown, forwardly and to the right to cover those parts of the apparatus mounted within the receptacle part of the cabinet (not shown). Said parts lie to the right of the hinge line H in the drawing. Within the box or receptacle part of the metal cabinet (not shown), there are mounted the two twenty-four hour clock-driven switching devices Cl and C2, both being constantly driven by 1 l5 V synchronous motors through the lead lin'es marked SM. Both switching devices are commercially available units, C1 being Model 8045-0 (Spec. No. A-335-O) and C2 being Model 400l-O (Spec. No. TD-1744-O), both made by the Paragon Electric Company of Two Rivers, Wis. Unit C2 bears US. Pat. No. 3,052,765, granted Sept. 4, 1962 to Everard et a1. If unit Cl should become unavailable, a unit constructed as described in us. Pat. N0. 1,902,570, granted to Mettler on Mar. 21, 1933, could be substituted therefor.

The timer device C1 has a dial 11 calibrated peripherally in hours and half hours (not shown) AM and PM, time being indicated by the tip of part 13 (marked TIME). The dial 11 has a circumferential series of threaded transverse apertures 15 located at two-hour spacings. Each aperture is adapted to receive screwheaded pins 17, the tips of which engage mechanism for closing the switch 19 located behind the dial ll. Said mechanism is adjustable by movement of the time selector 21 around the periphery of the serrated dics 23 fixed to the dial 11, so that each closing of the switch 19 can be preselected to last from 5 to minutes.

The timing switching device C2 (based on US. Pat. No. 3,052,765 to Everard et.al., Sept. 4, 1962), comprises an hourly calibrated (not shown) 24 hour dial rotatable under a fixed time indicating arm marked TIME. The clips marked ON and OFF" carry camming fingers (not shown) located at different radial distances from the periphery of the dial 25 so as to engage switch operating mechanism at the region of the tip of the TIME arm, as is fully disclosed in the Everard et al. patent noted above. The switch so operated is designated 27 and is located behind the dial 25. A manually engageable arm 28 is moved by the timing mechanism between its two disclosed positions, but it can also be manually moved to either position, if and when desired. The ON and OFF" clips are peripherally adjustably clamped to the edge of the dial 25 as by screws 29.

When the switch 27 is closed (during the dark or nearly dark hours), it energizes the solenoid coil of the relay R1 to energize the step-down transformer T (24 volts output) to operate the solenoid of a conventional valve to permit replenishing the evaporated water to the vat but only during night periods, flow being also controlled by a conventional float valve in fluid series with the solenoid valve. This provides a desirable safety feature because if the solenoid valve could open while the bed is flooded, the storage vat might overflow when the excess liquid of the flooding operation drains back into the vat.

When the switch 27 of the timer C2 opens at or near sunrise, it no longer disables the intermittent (day time) pumping control of the timer C1, which then is enabled to periodically energize the solenoid coil of the power relay R2 to run the conventional pump or pumps to flood the plant beds with nutrient solution from conventional vat or vats. B is an insulating strip for binding posts.

On the hinged cover panel C there are mounted a manual master power switch PS, an easily replaceable protective fuse F, a power-on amber light AL, a pumping-on red light RL, and a manual switch MS for bypassing the automatic controls to actuate the pumping circuit whenever desired.

The cover panel C also has mounted thereon a standard wall outlet-type socket which is energized whenever the pump circuit is energized. Thus a common or conventional self-starting electric clock C3 can be connected thereto permanently or periodically to meter and/or check the duration of each, or a series of pumping cycle(s).

What is claimed is:

1. In a hydroponic system comprising at least one plant bed and a storage vat means, electric pump means connected between said plant bed and said storage vat means for pumping nutrient solution to said plant bed from said storage vat means, means connected to said vat means for replenishing lost water to said vat means and including a solenoid-operated valve, the improvement comprising: a first clock switch means electrically connected to said pump means for periodically energizing said pump means, said first clock means being adjustable as to the time and the duration of each pumping cycle, a second clock switch means electrically connected to said first clock switch means and adapted to disable said first clock switch means adjustably between near sunset and near sunrise times, said second clock switch means being further augmented by means for permitting opening of said solenoid valve only during the time said first clock switch means is disabled by said second clock switch means, whereby said storage vat means is protected against possible overflowing by back drainage from a recently flooded bed into an already full vat means.

2. The invention according to claim 1, said first clock switch means, as well as said second clock switch means, being of the 24 hour type.

3. The invention according to claim 1, said waterreplenishing means including a float-operated valve in fluid-flow series with said solenoid-operated valve.

4. The invention according to claim 1 and additionally comprising a conventional self-starting, synchronous electric clock connected across said pump means to indicate the duration of one or a series of pumping cycle(s).

5. The invention according to claim 4, further including a conventional wall-type electric outlet for receiving a conventional plug-in connector on a clock cord.

6. The invention according to claim 1, in which both of said clock switch means are mounted on the forwardly facing rear wall of a shallow metallic box, and a pair of relays and a plurality of binding posts on a strip of insulation are also mounted in said metallic box.

7. The invention according to claim 6 and additionally comprising a laterally hinged cover panel on which additional circuit elements are mounted for easy operation and/or repair or replacement.

8. The invention according to claim 7, said additional elements including a protective fuse, a manual master power switch, a manual switch to close the circuit to said electric pump means at will, and at least one signal lamp to indicate the energized condition of at least one of said pump circuits and said system as a whole. 

1. In a hydroponic system comprising at least one plant bed and a storage vat means, electric pump means connected between said plant bed and said storage vat means for pumping nutrient solution To said plant bed from said storage vat means, means connected to said vat means for replenishing lost water to said vat means and including a solenoid-operated valve, the improvement comprising: a first clock switch means electrically connected to said pump means for periodically energizing said pump means, said first clock means being adjustable as to the time and the duration of each pumping cycle, a second clock switch means electrically connected to said first clock switch means and adapted to disable said first clock switch means adjustably between near sunset and near sunrise times, said second clock switch means being further augmented by means for permitting opening of said solenoid valve only during the time said first clock switch means is disabled by said second clock switch means, whereby said storage vat means is protected against possible overflowing by back drainage from a recently flooded bed into an already full vat means.
 2. The invention according to claim 1, said first clock switch means, as well as said second clock switch means, being of the 24 hour type.
 3. The invention according to claim 1, said water-replenishing means including a float-operated valve in fluid-flow series with said solenoid-operated valve.
 4. The invention according to claim 1 and additionally comprising a conventional self-starting synchronous electric clock connected across said pump means to indicate the duration of one or a series of pumping cycle(s).
 5. The invention according to claim 4, further including a conventional wall-type electric outlet for receiving a conventional plug-in connector on a clock cord.
 6. The invention according to claim 1, in which both of said clock switch means are mounted on the forwardly facing rear wall of a shallow metallic box, and a pair of relays and a plurality of binding posts on a strip of insulation are also mounted in said metallic box.
 7. The invention according to claim 6 and additionally comprising a laterally hinged cover panel on which additional circuit elements are mounted for easy operation and/or repair or replacement.
 8. The invention according to claim 7, said additional elements including a protective fuse, a manual master power switch, a manual switch to close the circuit to said electric pump means at will, and at least one signal lamp to indicate the energized condition of at least one of said pump circuits and said system as a whole. 